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Q:

A watch which gains uniformly is 2 minutes low at noon on monday and is 4 min.48 sec fast at 2 p.m on the following monday. when was it correct ?

A) 2 p.m on Tuesday B) 2 p.m on Wednesday
C) 3 p.m on Thursday D) 1 p.m on Friday

Answer:   B) 2 p.m on Wednesday

Explanation:

Time from 12 p.m on monday to 2 p.m on the following monday = 7 days 2 hours = 170 hours

\therefore The watch gains \inline \left ( 2+4\frac{4}{5} \right ) min. or  \inline \frac{34}{5} min. in 170 hrs.

Now, \inline \frac{34}{5} min. are gained in 170 hrs.

\inline \therefore 2 min are gained in \inline \left ( 170\times \frac{5}{34}\times 2 \right ) hrs = 50 hrs

\inline \therefore Watch is correct 2 days 2 hrs. after 12 p.m on monday i.e it will be correct at  2 p.m on wednesday.

Q:

The angle between the minute hand and the hour hand of a clock when the time is 8:30  

A) 80 Degrees B) 75 Degrees
C) 60 Degrees D) 105 Degrees
 
Answer & Explanation Answer: B) 75 Degrees

Explanation:

Angle traced by hour hand in \inline \frac{17}{2} hrs = \inline \left ( \frac{360}{12}\times \frac{17}{2} \right )^{o} = 255

Angle traced by min hand in 30 min = \inline \left ( \frac{360}{60}\times 30 \right )^{o} = 180

\inline \therefore Required angle = (255 - 180) = \inline 75^{o}

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21 2550
Q:

At what time, in minutes, between 3 o'clock and 4 o'clock, both the needles will coincide each other?

A) 11 4/11 B) 13 4/11
C) 15 4/11 D) 16 4/11
 
Answer & Explanation Answer: D) 16 4/11

Explanation:

At 3 o'clock, the minute hand is 15 min. spaces apart from the hour hand.
To be coincident, it must gain 15 min. spaces.55 min. are gained in 60 min.
15 min. are gained in
= (60/55 x 15)min
=16+4/11
The hands are coincident at 16 + 4/11 min past 3

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9 1546
Q:

How much does a watch lose per day, if its hands coincide ever 64 minutes?

A) 32 8/11 B) 33 8/11
C) 34 8/11 D) 35 8/11
 
Answer & Explanation Answer: A) 32 8/11

Explanation:

55min spaces are covered in 60min

60 min. spaces are covered in (60/55 x 60) min= 65+5/11 min.

loss in 64min=(65+5/11)- 64 =16/11

Loss in 24 hrs (16/11 x 1/64 x 24 x 60) min= 32 8/11.

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14 4447
Q:

A clock is set right at 8 a.m. The clock gains 10 minutes in 24 hours will be the true time when the clock indicates 1 p.m. on the following day?

A) 48 min. past 12. B) 46 min. past 12.
C) 45 min. past 12. D) 47 min. past 12.
 
Answer & Explanation Answer: A) 48 min. past 12.

Explanation:

Time from 8 a.m. on a day to 1 p.m. on the following day = 29 hours.

24 hours 10 min. of this clock = 24 hours of the correct clock.

 hrs of this clock = 24 hours of the correct clock.

29 hours of this clock =  hrs of the correct clock

= 28 hrs 48 min of the correct clock.

Therefore, the correct time is 28 hrs 48 min. after 8 a.m.

This is 48 min. past 12.

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83 9556
Q:

A clock is set right at 5 a.m. The clock loses 16 minutes in 24 hours.What will be the true time when the clock indicates 10 p.m. on 4th day?

A) 11pm B) 12pm
C) 1pm D) 2pm
 
Answer & Explanation Answer: A) 11pm

Explanation:

Time from 5 am. on a day to 10 pm. on 4th day = 89 hours.

Now 23 hrs 44 min. of this clock = 24 hours of correct clock.

356/15 hrs of this clock = 24 hours of correct clock

89 hrs of this clock = (24 x 31556 x 89) hrs of correct clock.

= 90 hrs of correct clock.

So, the correct time is 11 p.m.

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29 6940